Metal sheet shearing work method, pressed component manufacturing method, metal sheet, and shearing die for metal sheet

Abstract

A shearing work technology of metal sheets, such as high-strength steel sheets, is excellent in stretch flange crack resistance and delayed fracture resistance of the sheared end surface. A metal sheet shearing work method including: applying double shearing work to an end portion of at least one part of the metal sheet; and forming a first area having a cutting margin of a second shearing work of 5 mm or less in first cutting in the double shearing work. Second cutting in the double shearing work is carried out in a state where the movement on an end portion side of the first area is restrained. For example, by providing projection areas continuous to the first area and restraining the projection areas, the movement on the end portion side of the first area is restrained.

1 . A metal sheet shearing work method for shearing work a metal sheet, the method comprising:
 applying double shearing work to an end portion of at least one part of a metal sheet;   forming a first area having a cutting margin of second shearing work of 5 mm or less in first cutting in the double shearing work, and   carrying out second cutting in the double shearing work in a state where movement on an end portion side of the first area is restrained.   
     
     
         2 . A metal sheet shearing work method for shearing work a metal sheet, the method comprising:
 applying double shearing work to an end portion of at least one part of a metal sheet;   forming, in first cutting in the double shearing work, a first area having a cutting margin of second shearing work of 5 mm or less and a projection area continuous to the first area and having the cutting margin of the second shearing work larger than the cutting margin of the second shearing work of the first area due to a fact that the projection area projects with respect to the first area, and   carrying out second cutting in the double shearing work in a state where movement on an end portion side of the first area is restrained by restraining the projection area.   
     
     
         3 . The metal sheet shearing work method according to  claim 2 , wherein the restraint of the projection area is carried out by causing a guide member to abut on an end portion of the projection area. 
     
     
         4 . The metal sheet shearing work method according to  claim 2 , wherein, for the restraint of the projection area, formation of an opening in the projection area and insertion of a jig into the opening are carried out. 
     
     
         5 . The metal sheet shearing work method according to  claim 1 , wherein
 in the second cutting in the double shearing work, a guide member is caused to abut on an end surface of the first area to restrain the movement on the end portion side of the first area, and   an opening allowing passage of the guide member in a cutting direction is formed in an upper blade to be used in the second cutting.   
     
     
         6 . The metal sheet shearing work method according to  claim 1 , wherein the metal sheet has a tensile strength of 980 MPa or more. 
     
     
         7 . A pressed component manufacturing method comprising:
 when a metal sheet is formed into a pressed component through one or two or more times of press forming,   using a metal sheet sheared by the metal sheet shearing work method according to  claim 1  as the metal sheet.   
     
     
         8 . The pressed component manufacturing method according to  claim 7 , wherein the first cutting and the second cutting in the double shearing work are individually carried out before final press forming of the one or two or more times of press forming. 
     
     
         9 . A metal sheet, the metal sheet being press-formed after an end portion of at least one part is cut by shearing work, the metal sheet comprising, as the end portion to be cut,:
 a first area having a cutting margin of the shearing work of 5 mm or less; and   a projection area continuous to the first area and having the cutting margin of the shearing work larger than the cutting margin of the shearing work of the first area due to a fact that the projection area projects with respect to the first area.   
     
     
         10 . A shearing die for metal sheet, the shearing die cutting an end portion of a metal sheet with an upper blade in a state where the metal sheet is restrained with a lower blade and a sheet holder, the shearing die comprising:
 a restraining tool configured to restrain movement on an end surface side of the end portion to be cut.   
     
     
         11 . The shearing die for metal sheet according to  claim 10 , wherein
 the metal sheet has, as the end portion to be cut,:   a first area having a cutting margin of 5 mm or less; and   a projection area continuous to the first area and having the cutting margin larger than the cutting margin of the first area due to a fact that the projection area projects with respect to the first area, and   the restraining tool is configured to restrain the projection area.   
     
     
         12 . The shearing die for metal sheet according to  claim 11 , wherein the restraining tool has a guide member abutting on an end portion of the projection area. 
     
     
         13 . The shearing die for metal sheet according to  claim 11 , wherein the restraining tool has a rod body penetrating through the projection area. 
     
     
         14 . The shearing die for metal sheet according to  claim 10 , wherein the restraining tool has:
 a guide member configured to abut on the end surface of the end portion to be cut; and   an opening formed in the upper blade and allowing passage of the guide member in a cutting direction.   
     
     
         15 . The metal sheet shearing work method according to  claim 3 , wherein, for the restraint of the projection area, formation of an opening in the projection area and insertion of a jig into the opening are carried out. 
     
     
         16 . A pressed component manufacturing method comprising:
 when a metal sheet is formed into a pressed component through one or two or more times of press forming,   using a metal sheet sheared by the metal sheet shearing work method according to  claim 2  as the metal sheet.   
     
     
         17 . A pressed component manufacturing method comprising:
 when a metal sheet is formed into a pressed component through one or two or more times of press forming,   using a metal sheet sheared by the metal sheet shearing work method according to  claim 3  as the metal sheet.   
     
     
         18 . A pressed component manufacturing method comprising:
 when a metal sheet is formed into a pressed component through one or two or more times of press forming,   using a metal sheet sheared by the metal sheet shearing work method according to  claim 4  as the metal sheet.   
     
     
         19 . A pressed component manufacturing method comprising:
 when a metal sheet is formed into a pressed component through one or two or more times of press forming,   using a metal sheet sheared by the metal sheet shearing work method according to  claim 5  as the metal sheet.   
     
     
         20 . The shearing die for metal sheet according to  claim 12 , wherein the restraining tool has a rod body penetrating through the projection area.